Added keys and environment modules

src/environment.rs

@@ -0,0 +1,5 @@
+
+pub async fn get_db_url() -> String {
+    dotenvy::dotenv().ok();
+    std::env::var(crate::keys::DBURL).expect(crate::keys::error::ERROR)
+}

src/keys.rs

@@ -0,0 +1,5 @@
+pub const DBURL: &str = "DATABASE_URL";
+
+pub mod error {
+    pub const ERROR: &str = "DATABASE_URL must be set in .env";
+}